如何使用h:inputText +托管bean在JSF中保存列表/地图/集合 [英] How to save a list/map/set in JSF with h:inputText + managed bean
问题描述
我要实现的目标与以下链接中发布的目标非常相似.
What I'm trying to achieve is very similar to the one posted in the following link.
如何保存数组在JSF中使用ui:repeat + h:inputText +托管bean?
我对上面链接中的Arjan Tijms提供的答案特别着迷，但是我想要实现的目标略有不同.请考虑以下代码片段.
I'm particularly fascinated with the answer provided by Arjan Tijms in the link above however what I want to achieve is slightly different. Consider the following code snippets.
豆子
import javax.annotation.PostConstruct;
import javax.inject.Named;
import javax.enterprise.context.RequestScoped;
@RequestScoped
@Named
public class MyBean {
List<String> choices;
public List<String> getChoices() {
return choices;
}
@PostConstruct
public void initChoices() {
choices= new ArrayList<String>();
}
public String save() {
// should save all the choices into some repository
return "";
}
}
和方面页面
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:ui="http://java.sun.com/jsf/facelets">
<h:body>
<h:form>
<ui:repeat value="#{myBean.choices}" varStatus="status">
<h:inputText value="#{myBean.choices[status.index]}" />
</ui:repeat>
<h:commandButton value="Save" action="#{myBean.save}" />
</h:form>
</h:body>
</html>
问题是，如果我们在列表的开头有一些初始数据，这将起作用.初始列表为空的情况如何?
The thing is, this will work if we have some initial data in the list at the beginning. What about situations where the initial list will be empty?
我正在寻找的理想解决方案是每个选项都有1个h:inputText，然后单击保存"按钮，然后将每个h:inputText中的所有选项添加到选项列表中.我已经搜寻了很多东西，但似乎找不到任何提示.
The ideal solution which I'm looking for is to have 1 h:inputText for each choice and when save button is clicked, all choices in each h:inputText is then added to the choices list. I've searched high and low but can't seem to find any hints on how this can be done.
如果JSF 2确实不支持此功能，我想我将不得不仅用一个h:inputText来使用丑陋的方式，并使用转换器与列表进行相互转换，但我仍然希望这是一个理想的选择解决方案可以找到.
If JSF 2 really doesn't support this, I guess I'll have to use the ugly way with just one h:inputText and use a converter to convert to and from a list but I'm still hoping that an ideal solution can be found.
希望有来自stackoverflow的人可以向我介绍正确的方向.
Hopefully someone from stackoverflow can shed a light in the right direction for me.
推荐答案
只需添加一个添加"按钮即可向列表中添加新的String.
Just add an "add" button which adds a new String to the list.
<ui:repeat value="#{myBean.choices}" varStatus="status">
<h:inputText value="#{myBean.choices[status.index]}" />
</ui:repeat>
<h:inputText value="#{myBean.newChoice}" />
<h:commandButton value="Add" action="#{myBean.add}" />
<h:commandButton value="Save" action="#{myBean.save}" />
使用
private String newChoice;
public void add() {
choices.add(newChoice);
newChoice = null;
}
// ...
请注意，这仅在将bean放入视图范围内时才有效.将在每个请求上构造一个范围为一个请求的请求，从而每次都重新创建列表.
Note that this only works if bean is put in view scope. A request scoped one would be constructed on every request and hereby recreate the list everytime.
这篇关于如何使用h:inputText +托管bean在JSF中保存列表/地图/集合的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
